A conventional doorframe includes a door passageway, which is typically made of a pair of studs (e.g., wooden 2 by 4 studs nailed together or metal studs) covered by a casing made of ¾ of an inch boards, or metal casings in many commercial applications, forming a door jam. The door is hinged on one side of the housing with a doorknob and a door latch on the other side. The doorjamb leaves tight tolerances on all sides providing little space between the door and the door jam, yet still allows the door to function freely.
The door is secured into position with a door latch, which extends from the door and penetrates a hole, one-inch in diameter, in the casing and studs of the doorframe. The hole is aligned with the door latch and covered with a striker plate. The striker plate is generally 2 to 3 inches in length, made of metal and mortised and screwed into the casing of the door with ½ to ¾ of an inch long screws, which are easily stripped out. As a result of the tight tolerances and modification of the casing the installation of the striker plate is a customized operation. Therefore, the striker plate is difficult to reposition once it is installed. For the door and lock to function properly the door latch must fit into the hole of the striker plate. Misalignment of the door latch, the strike plate or both may result in serious security, health and safety risks in a door that will not close or open, latch or secure correctly.
As a consequence of age, humidity, foundation shifting and/or weather conditions buildings may move and cause doorframes to shift up and down and side to side. This movement results in misalignment of the relatively small hole of the striker plate and the door latch and/or the dead bolt latch. The misalignment often causes the door to be difficult or even impossible to secure. Additionally, the movement of the housing may result in the latch entering partially the striker plate and as a result may not adequately secure the door. In instances where the striker and door latch are semi-aligned, the interaction may be such that the friction is not sufficient to hold the door secure at such an imperfect position. In addition to the serious security problem caused by the misalignment, repeated attempts to reposition the striker plate may serious weaken the integrity of the doorframe and alter the aesthetic look of the door. Furthermore, even when the striker plate is moved, changes in conditions often cause the latch to return to its original position, causing the latch to misalign once again. Such changes are often observed and associated with changes in humidity.
One solution to the misalignment of the door latch and the hole of the striker plate includes the use of force (e.g., to pull the door up or push the door down or slam the door) to make the door latch and the striker plate hole align. Often doors that are forced to align result in doors that are just as difficult to reopen due to binding of the door, door latch, striker plate, or combination thereof. This problem is exacerbated when dealing with the elderly, children or the disabled, as they may not have the strength or the dexterity to supply the required force to align the door latch and striker plate hole. Furthermore, in times of emergency (e.g., a fire) a misaligned door and a lack of strength may preclude escape or cause the door to open during, e.g., a fire.
Other solutions to misalignments include adjusting the striker plate by redrilling the screw holes and remortising the striker plate to accommodate the new alignment position; most often resulting in the marring or destruction of the doorframe. Furthermore, reoccurring movement of the doorframe results in the process being repeated periodically, resulting in weak unsightly door jams.
The structure of a deadbolt latch and a door latch are quite different. The deadbolt has a larger diameter and a generally rectangular shape, which requires a matching striker plate hole. A door latch has a shorter, more rounded shape and corresponding striker plate. To further compound issues, some manufactures are designing door latches that incorporate the size and shape of the deadbolt latch. To change between these types new striker plates must be installed, which involves redrilling the screw holes and remortising the striker plate, often resulting in the marring or destruction of the doorframe.
The foregoing problems have been recognized for many years and while numerous solutions have been proposed, none of them adequately address all of the problems in a single device, e.g., multiple adjustments without reboring or remortising the doorjamb.